Method and arrangement of apparatus for oil recovery



Feb. 18, 1958 H. WALTER 2,823,752

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United States Patent METHOD AND ARRANGEMENT 0F APPARATUS FOR OIL RECOVERY Hellmuth Walter, Upper Montclair, N. .lL, assignor to Worthington Corporation, Harrison, N. 3., a corporation of Delaware Application August 30, 1955, Serial No. 531,567

5 Claims. c1. 166--11) The present invention relates to the recovery of petroleum oils from an oil reservoir and more particularly to the recovery of petroleum oils from partially depleted oil reservoirs.

In the recovery of petroleum oils from a crude residuum field which has been partially depleted so that the oil can no longer be extracted therefrom by the usual primary methods for economic reasons, it is common to resort to a secondary recovery method. A common secondary method of recovering oil from the partially depleted field comprises flowing a fluid under pressure into an input well to thereby force the residual crude oil in the reservoir to an output well where it may be readily extracted therefrom.

In accordance with the present invention, a method and apparatus for the secondary recovery of oil is provided having a prime mover connected to an air compressor, a gaseous fuel compressor, and a feedwater pump, to supply fuel, air to support combustion of the fuel, and feedwater to a combustion chamber to convert the water into steam. The waste heat in the prime mover exhaust gases is utilized to preheat the compressed air supplied to the combustion chamber for supporting combustion wherein while fluid used to cool the prime mover is passed into a feedwater preheater to remove the waste heat therefrom and to preheat the feedwater before it is pumped into the combustion chamber. In the combustion chamber, the gaseous fuel flowed thereto is fired to produce gases of combustion which convert the feedwater supplied to the chamber into steam, the gaseous products of combustion thereafter mixing with the steam to form a gas-steam mixture. The mixture is thereafter flowed to a turbine wherein it is expanded to a lower pressure to drive the turbine. The turbine is connected to the prime mover thus reducing the horsepower required by the prime mover to drive the compressors and feed pump. The gas-steam mixture is thereafter injected into the input well to force residuum remaining in the partially depleted reservoir to the output well where it may be extracted therefrom.

The present invention provides an apparatus for the recovery of crude oil from a partially depleted reservoir in an efiicient and economical manner.

The invention will be better understood from the following description when considered in connection with the accompanying flow diagram showing the apparatus embodied in the present invention.

Referring to the drawing, the reference numeral designates an internal combustion engine connected to an air compressor 11, a gaseous fuel compressor 12, and a feedwater pump 13 for driving the compressors and pump. Air compressor 11 is provided with an air inlet line 14 in communication with a source of air, not shown, and a discharge line 15 in communication with an air heater 16. Air heater 16 communicates with a combustion chamber 17 through line 18. The gaseous fuel compressor is provided with a gas inlet line 19 in communi ,cation with a source of gaseous fuel, not shown, and

a discharge line 20 in communication with the combustion chamber. Pump 13 has a suction line 21 in communication with a feedwater preheater 22 and a discharge line 23 in communication with the combustion chamber. Preheater 22 has a feed supply line 21a connected thereto and in communication with a source of water, not shown. The combustion chamber 17 is provided with a discharge line 24 in communication with a turbine 25 for passing a gas-steam mixture thereto. Turbine 25 is connected through a reduction gear 26 to the engine shaft to help drive the compressors and pump. A discharge line 27 connects the turbine with an input well 28 for flowing the gas-steam mixture discharged from the turbine to the well.

Engine 10 has a water supply line 29 for passing cooling fluid therethrough and a discharge line 30 connected thereto and in communication with preheater 22 for discharging cooling water therefrom to the preheater. Thus, the waste heat removed from the engine by the cooling water is passed in heat exchange relationship with the feed water supplied to the preheater to preheat the feedwater before it is flowed to combustion chamber 17. A cooling water outlet line 31 is connected to the preheater for discharging the water therefrom.

An exhaust gas line 32 is connected to engine 10 and air heater 16 to utilize the waste heat in the exhaust gases of the prime mover for preheating compressed air discharged from air compressor 11 before it is introduced into combustion chamber 17 to support combustion therein.

In operation, when internal combustion engine 10 is started it drives air compressor 11, gas compressor 12 and feedwater pump 13. The air compressor receives air from a source, not shown, through air inlet line 14, compresses it and discharges it therefrom through line 15 to air heater 16. Thereafter, the air passes in heat exchange relationship with exhaust gases flowing through the heater from line 32 of the engine and extracts the waste heat in the gases to increase the temperature of the air. The air then flows by line 18 to the combustion chamber 17 to support combustion therein.

The gaseous fuel compressor 12 receives fuel gas through inlet line 19 from a source, not shown, compresses it and thereafter delivers the gas through line 18 to the combustion chamber for firing therein.

Feedwater' is supplied to feedwater preheater 22 through inlet line 21a flowing therethrough in heat exchange relationship with cooling water passing into the preheater through line 30 connected to engine 10 and extracts the waste heat in the water to preheat the feedwater before it is passed to the combustion chamber. Thereafter, the feedwater flows through suction line 21 and is forced by pump 14 through discharge line 23 into the combustion chamber.

In the combustion chamber, the incoming gas fuel is ignited by means, not shown, and the products of combustion heat the incoming feedwater to convert it into steam. Thereafter, the products of combustion mix with the steam to form a gas-steam mixture which flows through line 24 to turbine 25 wherein it expands to a lower pressure to drive the turbine. The turbine and engine 10 connected thereto through gear 26 in turn drive the compressors and pump. Thus, the present in-' vention provides a turbine which utilizes a portion .of the energy in the gas-steam mixture to assist the prime mover and reduce the horsepower required by the prime mover to drive the air and fuel compressors and feed pump.

Thereafter the gas-steam mixture is discharged through line 27 from the turbine and flows into input well 28 to force residual crude oil remaining in the partially depleted oil reservoir from an output Well, not shown,

where it may be easily extracted therefrom. Thus, the present invention embodies apparatus for the recovery of oil from a partially depleted reservoir which is both eflicient and economical which utilizes the waste heat in the exhaust gases and cooling water of the internal combustion engine, and further provides a turbine utilizing a portion of the heat of compression in the gas-steam mixture to assist the engine and drive the compressors and feedwater pump.

It will be understood that changes may be ma i the form, location, and materials used in the construction of and arrangement of the various parts of the apparatus disclosed and in the steps of the process and other sequences disclosed herein without departing from the principles of the invention which is not to be limited excepting by the scope of the appended claims.

What is claimed is:

1. An arrangement of apparatus for recovering oil in a depleted reservoir comprising a combustion chamber for producing a gas-steam mixture for injection into the reservoir to force .oil therefrom, a gaseous fuel compressor incommunication with said chamber for supplying fuel to be fired thereto, an air compressor in communication with said chamber for supplying air thereto to support combustion, a feedwater pump in communication with said chamber for supplying feedwater thereto to be converted into steam, a prime mover connected to said compressors and pump for driving said compressors and pump, said prime mover having an exhaust line and a cooling fluid discharge line connected thereto, an air heater in communication with said exhaust line and said air compressor for flowing air therethrough in heat exchange relationship 'with exhaust gases passed therethrough from the prime mover, a feedwater preheater in communication with said discharge line and said pump for flowing feedwater therethrough in heatexchange relationship with cooling fluid passed therethrough from said prime mover, a gas-steam turbine con nected to said prime mover for driving said compressors and pump, a gas-steam line in communication with said combustion chamber and said turbine for flowing a gassteam mixture therethrough from said chamber to said turbine for driving the turbine, and a turbine discharge line connected to said turbine for injecting the gas-steam mixture into said reservoir.

2. An arrangement of apparatus for recovering oil in a depleted reservoir comprising a combustion chamber for producing a gas-steam mixture ,for injection into the reservoir to force oil therefrom, a gaseous fuel compressor in communication with said chamber for supplying fuel to be fired thereto, an air compressor having a discharge line in communication with said chamber for supplying air thereto to support combustion, a'feedwater pump in communication with said chamber for supply' ing feedwater thereto to be converted into steam, a prime mover connected to said compressors and pump for driving said compressors and pump, said prime mover having an exhaust line and a cooling fluid discharge line connected thereto, an air heater connected to said-exhaust line and said air compressor discharge line for flowing compressed air therethrough in heat exchange relationship with exhaust gases passed therethrough from the prime mover, a heated air conduit connected to said air heater and said chamber for passing heated airfrom said heater therethrough to said chamber, a feedwater preheater in communication with said cooling fluid discharge line and said pump for flowing feedwater therethrough in heat exchange relationship with cooling fluid passed therethrough from said prime mover, ,a gas-steam turbine connected to said prime mover for driving said compressors and pump, a gas-steam line in communication with said combustion chamber and said turbine for flowing a gas-steam mixture therethrough from said chamber to said turbine for driving the turbine, and a turbine discharge line connected to said turbine for injecting the gas-steam mixture into said reservoir.

3. An arrangement of apparatus for recovering oil in a depleted reservoir comprising a combustion chamber for producing a gas-steam mixture for injection into the reservoir to force oil therefrom, a gaseous fuel compressor having a discharge line connected to said chamber for supplying fuel to be fired thereto, an air compressor for supplying air to said chamber to support combustion, a feedwater pump having a discharge line connected to said chamber for supplying feedwater thereto to be converted into steam, a prime mover connected to said compressors and pump for driving the compressors and pump, an air heater having a discharge conduit connected to said chamber, a compressed air conduit connected to said air compressor to receive compressed air therefrom and with said air heater to discharge compressed thereto, an exhaust conduit connected to said prime mover to receive heated gases therefrom and with said air heater to discharge it thereto for passing the gases in heat exchange relationship with compressed air flowing through the heater, a feedwater preheater having a discharge line connected to said pump, a cooling water discharge conduit connected to said prime mover for -,receiving heated water therefrom and with said preheater to discharge it thereto for passing the heated water heat exchange relationship with feedwater flowing therethrough, a gas-steam turbine connected to said prime mover for driving said compressors and pump, a gassteam conduit connected to said combustion chamber to receive a gas-steam mixture therefrom and with said turbine to discharge it thereto to drive the turbine, and a discharge line connected to the turbine to receive the gas-steam mixture therefrom for injection into said depleted reservoir.

4. A method of injecting a gas-steam mixture into a depleted oil reservoir to force oil therefrom compr ising providing a source of power for flowing fuel, compressed air to support combustion, and liquid to be converted into steam into a combustion zone, firing the fuel in the combustion zone to produce a gas-steam mixture therein, flowing the gas-stream mixture intoan expansion zone to provide energy for .aiding in the flowing of sa id fuel, air, and liquid into said combustion zo n e, and thereafter flowing the expanded gas-steam mixture f n said expansion zone into said depleted oil 'reser 5. A method of injecting a gas-steam mixture iintoa depleted oil reservoir to force oil therefrom comprising providing a source of power for flowing fuel, ,and compressed air to support combustion, and liquid to be converted into steam into a combustion zone, transmitting heat energy emitted in said flowing operation to said air and liquid before entry into said combustion zone, firing the fuel in the combustion zone to produce a,gassteam mixture therein, flowing the gas-steam mixture into an expansion zone to provide energy for aiding in the flowing of said fuel, air and liquid into said ,cornbus tion zone, and thereafter flowing the expanded gas-steam mixture from said expansion zone into said depleted oil reservoir.

S rins n .=2 Walter Feb. 14, 1956 

4. A METHOD OF INJECTING A GAS-STEAM MIXTURE INTO A DEPLETED OIL RESERVOIR TO FORCE OIL THEREFROM COMPRISING PROVIDING A SOURCE OF POWER FOR FLOWING FUEL, COMPRESSED AIR TO SUPPORT COMBUSTION, AND LIQUID TO BE CONVERTED INTO STEAM INTO A COMBUSTION ZONE, FIRING THE FUEL IN THE COMBUSTION ZONE TO PRODUCE A GAS-STEAM MIXTURE THEREIN, FLOWING THE GAS-STEAM MIXTURE INTO AN EXPANSION ZONE TO PROVIDE ENERGY FOR AIDING IN THE FLOWING OF SAID FUEL, AIR, AND LIQUID INTO SAID COMBUSTION ZONE, AND THEREAFTER FLOWING THE EXPANDED GAS-STEAM MIXTURE FROM SAID EXPANSION ZONE INTO SAID DEPLETED OIL RESERVOIR. 